Highly efficient oxidation of synthetic and natural lignin-related compounds by Physisporinus vitreus versatile peroxidase

Versatile peroxidases (VPs) have outstanding oxidative capacity for a wide range of substrates and potential applications in industrial sectors and more. In this study, the VP1 from Physisporinus vitreus PF18 was obtained and overexpressed as inclusion body in Escherichia coli, then refolded successfully in vitro. Steady-state kinetic analysis and dye decolorization indicated that Mn(II) could promote the oxidation of low redox potential substrates and increase decolorization efficiency up to 70% by recombinant VP1 (rVP1). Results of pyrolysis-gas chromatography mass spectroscopy showed that most derivatives of G-type lignin increased slightly by rVP1 treatment, compared with the control. Surprisingly, the ratio of guaiacyl-type to syringyl-type derivatives (G/S) after rVP1 treatment was 5.4 times higher than that of the control. The polymerization of alkali lignin may be attributed to the transformation of S-type into G-type lignin by demethoxylation. Thus, our study provides a high-efficient candidate for biodegradation and biocatalysis.